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黄海波 《建筑·建材·装饰》2014,(17)
COD是化学需氧量的英文缩写,化学需氧量又称化学耗氧量,表示的是在强酸性的水溶液中,利用强氧化剂去氧化一升污水中有机物的耗氧量,通过耗氧量的多少可以计算出污水中有机物的含量。因此,化学耗氧量是判断水体货量,判断水体受有机物的污染程度的重要指标。当前 COD 检测的发展趋势决定着,在对污水水样采集之后,要尽快对其迚行COD检测,这样的检测结果才更准确,而愴国现阶段的检测方法耗时时间较长,使得检测结果不稳定。本文通过对愴国现阶段低浓度COD测定的研究发现,在一定的波长范围内,选取合适的消解液,用快速密闭消解加热装置代替敞开式的加热回流装置消解污水中的有机物,会使得低浓度COD的测定结果更加准确和稳定,而且检测过程简单、易操作,耗时短,费用低,检测结果更加满足分析要求。 相似文献
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文章对废水中CODCr测定方法中的快速消解/分光光度法、微波消解/分光光度法和回流消解/滴定法进行了比较.结果显示:快速消解/分光光度法和微波消解/分光光度法两种方法的准确度和精密度都达到质量控制的要求,两种方法分光光度法与回流消解/滴定法测定标准水样的方法相比,CODCr测定结果稍微偏高,但对于废水样品,两种方法的测定结果没有显著差异.快速消解/分光光度法和微波消解/分光光度法值得在环境监测工作中推广应用. 相似文献
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自配消解液分光光度法测定污水中COD 总被引:3,自引:0,他引:3
以自配消解液代替成本较高的HACH专用试剂,采用分光光度法测定了污水中的COD浓度,对影响测定结果的诸多因素进行了试验研究,确定了最佳操作条件。对比试验结果表明,该方法的测定结果与标准方法无显著性差异,适用于污水中COD浓度的测定。 相似文献
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密闭索因为其优势被逐渐应用到实际工程中,而密闭索索夹节点作为索结构中重要的连接节点,其抗滑移影响因素及索丝应力分布仍缺乏研究.通过数值模拟方法,将拉索类型、螺栓数量和索径对索夹节点抗滑移影响进行了分析,并通过建立密闭索、平行钢丝束和钢绞线的精细化模型,分析了索夹滑移过程中索丝的应力分布情况.结果表明:螺栓数量、索径和拉索类型对索夹滑移都有明显的影响;密闭索和钢绞线在索夹滑移过程中索丝应力变化较大,索夹滑移方向一侧索丝应力减小,另一侧索丝应力增大,而平行钢丝束由于HDPE保护层的作用,索丝应力并未发生明显变化. 相似文献
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针对污水处理厂出水COD测量中的氯离子干扰问题,从测定原理、消除效果及适用范围等方面对常用的几种标准方法进行了比较,并对筛选出的适用方法进行了实践.结果表明,低浓度氧化剂法、氯气校正法的结果相近,是测定污水厂高浓度氯离子出水中COD的可行方法. 相似文献
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综述了影响污水COD去除效果的各个因素,着重对混凝剂选择、投加量的确定以及水力条件等方面进行了阐述,并结合我国市政污水处理的现状,提出有效提高污水COD去除率的可能措施。 相似文献
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Kinetics of electro-oxidation of ammonia-N, nitrites and COD from a recirculating aquaculture saline water system using BDD anodes 总被引:3,自引:0,他引:3
The viability of the electro-oxidation technology provided with boron doped diamond (BDD) electrodes for the treatment and reuse of the seawater used in a Recirculating Aquaculture System (RAS) was evaluated in this work.The influence of the applied current density (5-50 A m−2) in the removal of Total Ammonia Nitrogen (TAN), nitrite and chemical oxygen demand (COD) was analyzed observing that complete TAN removal together with important reductions of the other considered contaminants could be achieved, thus meeting the requirements for reuse of seawater in RAS systems.TAN removal, mainly due to an indirect oxidation mechanism was described by a second order kinetics while COD and nitrite removal followed zero-th order kinetics. The values of the kinetic constants for the anodic oxidation of each compound were obtained as a function of the applied current density (kTAN = 7.86 × 10−5·exp(6.30 × 10−2 J); k2NO = 3.43 × 10−2 J; kCOD = 1.35 × 10−2 J). The formation of free chlorine and oxidation by-products, i.e., trihalomethanes (THMs) was followed along the electro-oxidation process. Although a maximum concentration of 1.7 mg l−1 of total trihalomethanes was detected an integrated process combining electrochemical oxidation in order to eliminate TAN, nitrite and COD and adsorption onto activated carbon to remove the residual chlorine and THMs is proposed, as an efficient alternative to treat and reuse the seawater in fish culture systems. Finally, the energy consumption of the treatment has been evaluated. 相似文献
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The removal efficiencies of nitrogen, phosphorus and COD from waste water were examined using sand filtration systems with Phragmites australis (Cav.) Trin. ex. Steudel. The quality of effluent waters from the system with plant were far better than those from the one without plant, implying Phragmites could incorporate nitrogen and phosphorus into its tissues and promote phosphorus absorption onto the sand by the release of oxygen from the roots. The P-pot provided with the influent containing 198 mg l- of total nitrogen and 21 mg l-1 of total phosphorus had the highest biomass of Phragmites. Harvestable above-ground biomass accounted for about 3.5 kg m-2 and removable nitrogen and phosphorus accounted for 69 and 6 g m-2 respectively.The removal rates of total nitrogen and phosphorus in the system with Phragmites receiving variable amounts of COD were almost at the same level and also much better than those of the systems without plant, implying that the different COD concentrations in the influent media do not impair the removal efficiencies of nitrogen and phosphorus. Also Phragmites was found to resist COD concentration as high as 128 mg l-1, and signs of clogging were not detected in this system throughout the experiment. 相似文献
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对某大型酒店排水COD浓度实施24h监测,监测结果显示楼外总排水口1日间COD浓度在200~1000mg/L范围内变化,12:00~14∶00时为最高峰值段COD浓度高达700~1000mg/L,0∶00~2∶00时为次高峰值段COD浓度高达400~700mg/L,其它时间段COD浓度在200~400mg/L范围内变化。中餐厨房和西餐厨房排水COD浓度全天在880~1350mg/L范围内变化。本文讨论了总排水口COD浓度大幅动态变化的主要影响因素和形成原因,中餐厨房和西餐厨房排水COD浓度是影响酒店排水水质的最主要影响因素。 相似文献